Locomotive draft duct



Patented July 2, 1940 UNITED STATES PATET cries 6 6 2,206,263 l toooMo'nvE DRAFT DUCT Leland G. Plant, Washington, 0. Application August 1, 1938, Stem. 222,566 6 7 Claims (01. 1 44-52 1 This is an invention in constructionandane rangemcnt of draft ducts, branching from the inlet of an induced-draft type fan mounted on an enginehouse roof, to draft-tight connections 5 made automatically with smoke stacks of locomotives entering the house. 6

The object of this invention is to improve upon structural and functional features of locomotive drafting devices in which ductsare used to convey smokeand gasses from the locomotive stack to a power driven fan, capable of inducing a draft in the locomotive firebox, and discharging the products of combustion therefrom, outside the enginehouse. 6 6 6 The advantage of removing locomotive; smoke andgas from an enginehouse thru closed ducts in draft-tight connection with the locomotive smoke stacks, instead of dischargingthese products of combustion thru open vents in the enginehouse roof, has long been appreciated. Induced draft fans have been providedfor this purpose, both in the arrangement of a fan individually applied to each stack and of onefan connecting with a plurality of stacks thrua series of open .5 ings in a duct. Both of these arrangements are subject to objections which are effectively overcome by'th-e present invention.

A draftduot leading from aseries of locomotive stack connections to a single fan, must have H) an increasing cross-area approaching the fan. ,When such a systemis being run to accommodate only *aminority of the locomotives for which stack connections areprovided, the equipment is oversize and inefficient for such service. Where an individual fan is provided for each locomotive position, the initial installation cost is disproportionably high in relation to the average service requirements. Fan units adapted to be moved from locomotive to locomotive, involve additional labor and dependupon having open vents in the enginehouse roof. I In this invention, one fan serves a plurality of: locomotives, each thru an individual duct, properly dimensioned for most ei'ficiently draft- 5 ing a single locomotive. In a groupof locomotives served by one fan, it provides for selectively directing the fiow of gasses from any one stack, either to the fany or directly to atmosphere thru an outlet abovethe enginehouse roof. 0 j Where individual fans are provided on an'enginehouse roof above each locomotive stack, the

entire weight of each motor and fan mechanism has to be supported by the roof at a point approximately midway between the rows of :sup-

5 porting posts in the enginehouse structure. This above the roof.

necessitates a heavier roof structure'than would otherwise be required and in existing buildings, the roof has often to be reinforced substantially to carry such additional weight. In my arrangement, a fan for serving two or more adjacent 5 tracks can beplaced directly over the row of roof supporting posts between said tracks.

With mechanical drafting of locomotives in an enginehouse, it isdesirableto have means 'for automatically connecting and disconnecting the draftiduct, as a locomotive moves in and out of the enginehouse. Itis alsodeshable to allow for movementof the stacka few feet forward or back, while work is being done on the locomotive, without disturbing its contact with 15 the draft duct. Myinvention accomplishes this in a novel and effective manner. It employs the old device of a semi-spherical surface, seating upon the inner rim of thelocomotive stack, combined with the new design of a yoke engaging the stack in a self-centering manner and counterweightedat such a leverage angle as to compel the semi-spherical surface to seat fully into the stack, as the locomotive moves forward under the duct.

6 p 6 Movement of the duct in contact with a stack,

to accommodate movement of the locomotive is here provided for, as in older devices, by designing one section of the duct to telescope within another and suspendingthese sections from a pivot, so that the duct isiree to swing radially and its lower section to move horizontally with the stack In combination with this construction, I introduce a novel hatch construction for an enginehouse roof structure, thru which the 5 duct is free to swing in an are from the pivot Without this innovation, it is necessary, as in previous constructions, to keep the pivot point below the roof and where the roof is low, in relation to the locomotive stack heighth, considerable expense is incurred for raising the roof structure around the suspended duct, to allow for its swinging thru an arc, suilicient to accommodate some movement of the 10- comotive Without breaking its connection with the stack. l 6 l This invention provides a duct structure that can be built of cylindrical pipe sections, hence economically adapted to fabrication from noncorrodible material, such as Transite pipe. It is also adapted to an assembly in which the joints between sections can be madedraft tight by fabric connectors of non-inflammable material, such as glass cloth. 6 Thesefeatures are not exclusively adapted to my structura but I am the first to propose and disclose their use in combination with a draft duct device for automatically contacting the stacks of locomotives as they move into an enginehouse.

In the drawing of this invention, Figure 1 shows a section of the enginehouse roof R, spanning two adjacent locomotive positions. The stacks K of locomotives L, are shown in these positions and post P, supporting said roof midway between the locomotive positions. Figure 2 is a sectional view of said enginehouse, in a plane at right angles to the first figure, showing one of the locomotives L, with its stack at various positions K, K-I and K-2, in contact with the duct device of this invention. In these views, S represents structural steel members on roof R, for supporting the draft duct device and T is a rectangular opening in said roof surrounded by .a horizontally topped coping. In these Figures 1 and 2, the numerals apply to principal parts of this draft device as follows:

I Semi-spherical seating surface with oval opening, adapted to seat in locomotive stacks of various sized openings, and to rest at various angularities upon said stacks, in draft-tight contact therewith.

2 Lower section of swinging draft pipe, attached to semi-spherical surface I, and telescoping over the section above.

3 Fabric connector of non-inflammable material, affording a flexible, but draft-tight connection between section 2 and v 4 Upper section of draft pipe, swinging from a pivot above the roof; open at top and telescoping into section 2 at its lower end.

' 5 Horizontal section of draft pipe, connecting into section 4, and branching transversely therefrom, along the axis upon which the swinging section is pivoted.

6 Damper at upper end of section 4, controlling its opening to atmosphere.

I Damper in transverse branch from section 4, controlling its opening into section 5.

8 Interlocking lever between dampers B and "I,

' requiring closure of one damper while other is open.

9 Horizontal section of draft pipe, telescoping over transverse branch 5, from section 4, and extending therefrom to IEI Draft fan with its motor mounted above enginehouse roof, on supports S, and connecting 1 I, by interlocking lever 8.

, I2 Trunnion upon which the swinging duct section 4, is pivoted on one side, opposite transverse branch section 5, which serves as trunnion support for said section on its other side.

I3 Rollers mounted on supports S, above roof R,-in position to cradle the trunnion I2 and section 5, as pivots for the swinging duct section 4, suspended therefrom.

54 Cover plate resting on coping of roof opening T. The swinging duct section 4, passes thru duct section 2.

I'I Yoke pivoted to trunnion IS, with a loop curved below this pivot to engage the stack K,

of locomotive L. Extending in the other direction from said trunnion, this yoke has a rigid length, acting as a lever upon trunnion I6, with itscontact upon stack K as the fulcrum, when attached to a counterweight cord, carried thru pulleys to i I8 Counterweight hanging alongside enginehouse post P. This counterweight is of sufiicient weight to draw the swinging duct section 4, with its dependent section 2, and stack contacting surface I, up to an angle at which it will clear the locomotive stack K, when the yoke I1 is not in contact therewith.

As a locomotive L, moves into the positions indicated on Figure 2, the contact of its stack K, with yoke I'I, draws up the counterweight I8, and permits the draft duct sections to swing downward until the semi-spherical surface I first rests in sealing contact upon the inner rim of stack K, then, as the locomotive continues to move forward, the pull of counterweight I8, upon the lever arm of yoke I'I, tends to pitch the trunnion I6 forward so that for any angularity of the swinging duct sections and surface I, within range of stack K, said surface will rest upon said stack in full annular'contact with its inner rim.-

In the regular operation of this draft duct device, a locomotive to be drafted is moved into the enginehouse and asit approaches the position at which it is to be stationed, its stack draws the swinging duct into draft tight contact therewith, for any position occupied, wherein its stack is within a few feet of a vertical line thru the pivot point from which it is suspended. The fan I0, induces a draft upon the locomotive, when damper B is closed and damper 1 is opened, the fan being'set in motion by a control switch located in the enginehouse.

If desired to have the fan exert its full induced draft force upon another locomotive, with which it has draft duct connection, damper 6 may be opened and damper I closed. With the dampers in that position, this locomotive is independentv of the induced draft fan and may be drafted by its own blower nozzle, or held in any condition desired with its stack in open communication to the atmosphere above the enginehouse roof, but

without many objectionable features associated with the customary opensmoke vents in an enginehouse roof.

For this invention, I claim:

1, In an enginehouse, a draft fan, a fan suction duct having a communicating swinging duct section suspended from pivot bearings by which it is supported above the enginehouse roof, an opening in" said roof thru whichv said section can swing in an arc, a cover plate for said opening, a'hole in said cover plate thru which said duct section can turn in an arc, said plate being-free t slide back and forth upon a coping surrounding said roof opening, as required to accommodate the swinging movement of the duct section passing thru said hole, without uncovering said roof opening; a telescoping ductexten sion upon the lower end of said swingingsection and a semi-spherical stack contacting surface uponthe lower end of said extension, adapted to' rest at various angles uponthe inner rim of a locomotive stack, in full annular contact therewith,and an opening in, said surface so shaped that it will not be exposedabove the rim of said Stack, at any angle of the surface while in contact with a locomotive stack. 1

2 In an enginehouse, a draft fan, a fan suction duct having a communicating swinging duct section suspended from pivot bearings by which it Q is "supported above the enginehouse roof, an

in saidcover for the passage of said swinging duotsection, and a telescoping duct] extension opening in said roof thru which said section can swing in an arc, a slidable' cover for said opening adapted to move with said duct section, a hole upon the lower end of said swinging section, said extensionbeing adapted at its lower end to establish eiiectively draft-tight connection with a locomotive stack, automatically, as the 1000- l motiveapproaches its parking position, and to, automatically disconnect itself from said stack when the locomotive is moved from the enginehouse. t

3. In an enginehouse orthe like having a roof opening thereinQa smoke jack extending through said roof opening, meansabove the roof opening for swingingly supporting the jack and a slidable cover for said roof opening having an opening forsaid jack, said cover being adapted to slide with said jack whenever the jack swings.

4. In an enginehouse, a swingingly supported smoke jack extending through an opening in thefroof of. the enginehouse, said smoke jack including a pair of laterally extending trunnions near the top thereof, bearings for said trunnions located above the roof opening of said enginehouse, and a sliding cover for said roof opening,

having an opening through which the jack projects, said cover being adapted to slide with the jack whenever the jack swings.

l 5. A smoke jack as set forth in claim 4,, wherein one of the trunnions comprises a pipe conand a joint connector for said telescoping members comprising a skirt of flexible non-inflammable draft tight material connected at its ends to the telescoping members. I

, 7 In an enginehouse or the like having a roof opening therein, a smoke jaokextending through said roof opening, means above the roof opening for swingingly supporting the jack and a opening for said jackpsaid cover being adapted to slide with said jack Whenever the jack swings,

and means for flexibly connecting the cover to said jack comprising a fluid tight fabric skirt of non-inflammable material connected at one end to the jack and at the other end to the slidable cover. i

PLANT, 40,

slidable cover for said roof opening having an 

